JP3388665B2 - Continuous lightweight improvement method for deep ground - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous ground light weight improvement method for deep ground, which continuously improves the weight of the deep ground and reduces its weight.

[0002]

BACKGROUND OF THE INVENTION Basically, a method for improving the weight of the ground to a deep depth and reducing the weight is
Repeat the process of temporarily discharging the ground to be improved to the ground, mixing the discharged soil and the ground improvement material such as cement-based solidifying material and the foam beads on the ground, and then returning the mixture to the ground. Be seen.

[0003] Specifically, soil and sand within a range to be improved are collected by an excavator such as a backhoe, and this is mixed with a ground improvement material and foam beads or a foaming agent in a ground mixing plant to obtain a mixture of improved sand and sand. A method of returning to the original position, and while the soil was discharged with an August cru as in Japanese Patent Laid-Open No. 5-255924, which was previously proposed by the applicant, it was prepared by mixing the ground improvement material and the foam beads in the ground mixing plant. There is a method of pumping the improved lightweight soil with a pump and replacing the original ground with the improved lightweight soil.

Since the method of (1) is carried out prior to the excavation of the ground, it cannot be applied from the economical aspect up to the depth at which the earth retaining work is required at the time of excavation. Since the slope is likely to collapse during excavation in the ground where the groundwater level is relatively high because no earth retaining works will be applied, the applicable depth will be shallow, and the target ground is practically limited to the shallow layer.

Further, since the excavated soil is mixed on the ground, the cost is higher than the stirring and mixing method performed in-situ.

Since the method of (1) uses pumping, it is necessary to secure the fluidity of the lightweight modified soil mixed in the above-ground mixing plant, and at the same time, to adjust the quality so that the lightweight expanded beads do not separate the materials. Advanced quality control technology is required. Further, as the amount of foam beads added increases, there is a disadvantage that pumping becomes difficult due to the compressibility of the beads themselves.

[0007] The method of (1) can be improved to deep ground because the excavation is performed by August cruw, but since the mixing is performed in the ground mixing plant as in the method of (1), the cost is higher than the stirring and mixing method performed in-situ.

The present invention proposes a method capable of improving lightweight soil to deep soil at low cost from the above background.

[0009]

In the present invention, while cutting the ground using an endless chain having cutting and stirring blades protruding from the outer periphery, the ground improving material and foam beads are put into the cutting ground,
By mixing as it is, the mixing in the mixing plant on the ground is not required, and it is possible to improve the lightweight improved soil even to the deep ground while reducing the cost.

The endless chain is stretched around the upper and lower ends of the posts mounted on the base machine in a freely circulating manner, and the cutting soil is stirred and mixed with the ground improving material and the foam beads while cutting the ground on the outer periphery thereof. A cutting and stirring blade is projected.

The post faces the vertical direction or a direction inclined with respect to the vertical direction, and is mounted on the base machine so as to be vertically movable in that direction. Construction is carried out by circulating the endless chain while moving the post relative to the ground.

To mix the earth and sand cut by the circulating endless chain cutting and stirring blades with the ground improving material and the foam beads, only the ground improving material and the foam beads are put into the cutting ground from the descending side of the endless chain. The cutting and stirring blades are used as they are.

Since the depth of the target ground is not limited because the ground is improved by the endless chain, and it is possible to construct up to the depth of about the length of the post, it is possible to improve the lightweight improved soil up to the deep ground. Improvements are possible.

Since the cutting soil and the ground improvement material and the foam beads are stirred and mixed in-situ by the cutting stirring blade, it is not necessary to discharge the cutting soil to the ground and to mix it on the ground.

Since the cutting soil is not required to be discharged and the earth retaining work is unnecessary, the construction can be carried out regardless of the height of the groundwater level.

Further, the ground improvement material and the foam beads are agitated and mixed with the cutting soil only by being put into the cutting ground.
Since no mixing on the ground is required and no special charging means such as pumping is required, the construction method and construction equipment can be simplified and the cost can be reduced.

In addition, since there is no pumping, regardless of the state of the input material, the ground improvement material is charged in a powder state or in a slurry state, the foam beads are in a granular state, or mixed with the ground improvement material. it can.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as shown in FIG. 1, a post 2 mounted on a base machine 1 in a vertically movable manner is circulated around the upper and lower ends of the post 2 in a circulating manner, and a cutting and stirring blade 4 is provided on the outer periphery of the post. It is a method of continuously improving the deep ground to light soil by using the endless chain 3 thus prepared.

The post 2 faces the vertical direction or a direction inclined with respect to the vertical direction, and is supported by the base machine 1 so as to be vertically movable in that direction.

The construction is carried out by circulating the endless chain 3 and cutting the ground with the cutting and stirring blades 4, while introducing the ground improvement material 5 and the foam beads 6 into the cutting ground from the descending side of the endless chain 3. By the circulating cutting and stirring blade 4, the cutting soil, the ground improving material 5 and the foam beads 6 are stirred and mixed as they are, and the ground is continuously improved into lightweight soil.

FIG. 1 shows a case in which the section located on the front side of the post 2 in the horizontal traveling direction is circulated in the descending direction.
The direction in which the endless chain 3 circulates does not matter, and in some cases it may circulate in the opposite direction, and the ground is improved in any direction according to the direction of the post 2.

As the ground improvement material 5, a lime-based ground improvement material is used in addition to the cement-based solidifying material, and the ground improvement material 5 is put in a slurry state or in a powder state.

The foam beads 6 are of styrene type or polyvinylidene chloride type, but the material is not limited. The foam beads 6 are added in a state of being mixed with the ground improvement material or individually.

In FIG. 2, powder ground improvement material 5 and foam beads 6 are simply laid on the ground near the construction direction of the post 2, and the movement of the post 2 causes the cutting and stirring blade 4 to cut the ground simultaneously with the improvement of the ground. A method of introducing the material 5 and the foam beads 6 into the cutting soil will be described.

FIG. 3 shows a method in which only the foam beads 6 are laid on the ground, and the ground improvement material 5 is charged in a slurry state using a flexible pipe 7. In the method using the pipe 7, the ground improvement material 5 may be pneumatically fed as a powder.

FIG. 4 shows a method in which the ground improvement material 5 in a slurry state and the foam beads 6 are mixed in advance, and both are charged using a pipe 7, or a mixture of the powder ground improvement material 5 and the foam beads 6 is used. A method of pneumatically feeding

[0027]

[Effects of the Invention] Since the ground is improved by using an endless chain that can be constructed to a depth of about the length of the post, the depth of the target ground is not limited, and it is possible to improve the lightweight soil up to the deep ground. It is possible, and even in the case of soil in which the soil is alternately layered in the depth direction, it can be improved uniformly in the depth direction.

Since the cutting soil and the ground improvement material and the foam beads are stirred and mixed in-situ by the cutting stirring blade, it is not necessary to discharge the cutting soil to the ground and to mix it on the ground.

Since the cutting soil is not required to be discharged, the earth retaining work is not required, and therefore the construction can be performed regardless of the height of the groundwater level.

Since the ground improvement material and the foam beads are only put into the cutting ground and are not agitated and mixed with the cutting soil and mixing on the ground is required, the construction method and the construction equipment can be simplified and the cost can be reduced. Can be reduced.

Since there is no pumping, regardless of the state of the input material, the ground improvement material remains in a powder state or in a slurry state, the foam beads remain in a granular state, or a state mixed with the ground improvement material. But you can throw it in.

[Brief description of drawings]

FIG. 1 is an elevational view showing a base machine and a construction procedure.

FIG. 2 is an elevational view showing an example of charging a ground improvement material and foam beads.

FIG. 3 is an elevational view showing an example of charging a ground improvement material and foam beads.

FIG. 4 is an elevational view showing an example of charging a ground improvement material and foam beads.

[Explanation of symbols]

1 ... Base machine, 2 ... Post, 3 ... Endless chain, 4 ... Cutting stirring blade, 5 ... Ground improvement material, 6 ... Foam beads, 7 ... Pipe.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A 5-280043 (JP, A) JP-A 5-255924 (JP, A) JP-A 58-127829 (JP, A) JP-B 43- 28153 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) E02D 3/12 102

Claims (3)

(57) [Claims] 1. A post, which is oriented in a vertical direction or a direction inclined with respect to the vertical direction, and is vertically movable in the direction, and is stretched around the upper end and the lower end of the post so as to be circulated, and a cutting stirring blade is provided on the outer periphery. by using the base machine fitted with an endless chain was, is a method of moving the post to improve continuously to the lightweight improved soil deep ground, the land of the construction direction side of the post
A ground improvement material of powder and foam beads are laid on top, the endless chain is circulated, the post is moved, and the cutting stirring blade
By cutting the ground with, the ground improvement material and foam beads are put into the cutting ground from the descending side of the endless chain, and the cutting soil, ground improvement material and foam beads are stirred by the circulating endless chain cutting and stirring blades , Continuous ground lightweight improvement method for deep ground to be mixed. 2. A post that faces in the vertical direction or a direction inclined with respect to the vertical and is vertically movable in that direction, and is stretched around the upper end and the lower end of the post so as to be able to circulate, and a cutting stirring blade is provided on the outer periphery. by using the base machine fitted with an endless chain was, is a method of moving the post to improve continuously to the lightweight improved soil deep ground, the land of the construction direction side of the post
Lay foam beads on top and slurry the ground improvement material
Posts can be made in the state or in powder form using a pipe.
Send it to the ground near the work direction , circulate the endless chain,
Move the post and cut the ground with the cutting agitator.
With, the ground improvement material from the descending side of the endless chain
An endless chase in which foam beads are put into the cutting ground and circulate.
A continuous ground lightweight improvement method for deep soil, in which the cutting soil, ground improvement material and foam beads are agitated and mixed by the cutting and stirring blades . 3. A post that faces the vertical direction or a direction that is inclined with respect to the vertical direction, and that is vertically movable in that direction, and is stretched around the upper end and the lower end of the post so that it can circulate freely, and a cutting stirring blade is provided on the outer periphery. Using a base machine equipped with an endless chain that has been installed, it is a method of continuously improving the deep ground to lightweight improved soil by moving the post, in the slurry state, or
With the powder ground improvement material and foam beads mixed in advance,
Using pipes to the ground near the post construction direction
Feed, circulate the endless chain, move the post and cut
By cutting the ground with a cutting and stirring blade, the ground improvement material and foam beads are put into the cutting ground from the descending side of the endless chain, and the cutting and stirring blade of the circulating endless chain improves the cutting soil and ground. A continuous ground lightweight improvement method for deep ground where materials and foam beads are agitated and mixed.